Darrah P S, DiMarco N M, Beitz D C, Topel D G
J Nutr. 1979 Aug;109(8):1464-8. doi: 10.1093/jn/109.8.1464.
Rates of conversion of lactate, alanine and aspartate to glucose and oxidation of each to CO2 were determined in incubated liver slices from nine stress-susceptible (SS) and seven stress-resistant (SR) Yorkshire pigs ranging in body weight from 24 to 54 kg. Pigs were screened for stress susceptibility by exposure to halothane at 7 weeks of age. Stress was minimized before slaughter, and liver samples were obtained immediately after death. Rates of lactate and aspartate conversion to glucose were not significantly different between pig types. Mean rates of lactate conversion to glucose in livers of SS and SR pigs were 637 and 413 nmoles/(100 mg X 2 hours), respectively. Mean rates of aspartate conversion to glucose were 441 and 540 nmoles/(100 mg X 2 hours) in SS and SR pigs, respectively. Alanine conversion to glucose in livers of SS pigs was slower than that in SR pigs [527 and 813 nmoles/(100 mg X 2 hours), respectively]. Rates of hepatic gluconeogenesis from lactate probably do not predispose SS pigs to the lactic acidosis observed during the porcine stress syndrome. Rates of lactate, alanine and aspartate oxidation to CO2 in livers of SS pigs were 61, 59 and 76%, respectively, of the rates observed in SR pigs. Decreased rates of substrate oxidation to CO2 may contribute to the development of the syndrome in SS pigs.
测定了体重在24至54千克之间的9头应激敏感型（SS）和7头应激抵抗型（SR）约克夏猪的肝脏切片中乳酸、丙氨酸和天冬氨酸转化为葡萄糖的速率以及各自氧化为二氧化碳的速率。在7周龄时通过接触氟烷对猪进行应激敏感性筛选。屠宰前尽量减少应激，死后立即获取肝脏样本。猪的类型之间乳酸和天冬氨酸转化为葡萄糖的速率没有显著差异。SS猪和SR猪肝脏中乳酸转化为葡萄糖的平均速率分别为637和413纳摩尔/（100毫克×2小时）。SS猪和SR猪中天冬氨酸转化为葡萄糖的平均速率分别为441和540纳摩尔/（100毫克×2小时）。SS猪肝脏中丙氨酸转化为葡萄糖的速度比SR猪慢[分别为527和813纳摩尔/（100毫克×2小时）]。肝脏中由乳酸生成葡萄糖的糖异生速率可能不会使SS猪易患猪应激综合征期间观察到的乳酸酸中毒。SS猪肝脏中乳酸、丙氨酸和天冬氨酸氧化为二氧化碳的速率分别为SR猪中观察到速率的61%、59%和76%。底物氧化为二氧化碳的速率降低可能导致SS猪出现该综合征。
